The effect of particle size in the adsorption of carbon monoxide on iridium: An infrared investigation

Toolenaar, F.J.C.M.

doi:10.1016/0021-9517(83)90115-x

Cited by 67 publications

(21 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar ndings have been reported in previous studies. 17,29,30 Indeed, Toolenaar et al 29 investigated the adsorption of CO on the Pt-Cu/Al 2 O 3 catalyst and observed the downward shi of the CO/Pt band, which was caused by the geometrical effect altering the interaction between Pt and Cu, consistent with our results.…”

Section: Characterization Of Fresh Catalystssupporting

confidence: 91%

“…The higher energy band at around 2064 cm À1 is associated with the CO linearly bound to the terraces or planes that are coordinatively saturated, 31,32 while the broad band around 2032 cm À1 is assigned to the CO adsorbed at the corners or apex atoms that are coordinatively unsaturated. 22,32 Compared to the Pt/Al 2 O 3 catalyst, the Cu addition results in a downward shi of the CO band to 2058 cm À1 with the two resolved peaks shied to 2059 and 2021 cm À1 , while a relatively weak CO adsorption at 2160 cm À1 that can be assigned to CO/Cu bands 29,33,34 is also observed in Fig. 3b.…”

Section: Characterization Of Fresh Catalystsmentioning

confidence: 82%

See 1 more Smart Citation

Propane dehydrogenation over Pt–Cu bimetallic catalysts: the nature of coke deposition and the role of copper

et al. 2014

View full text Add to dashboard Cite

This paper describes an investigation of the promotional effect of Cu on the catalytic performance of Pt/Al2O3 catalysts for propane dehydrogenation. We have shown that Pt/Al2O3 catalysts possess higher propylene selectivity and lower deactivation rate as well as enhanced anti-coking ability upon Cu addition. The optimized loading content of Cu is 0.5 wt%, which increases the propylene selectivity to 90.8% with a propylene yield of 36.5%. The origin of the enhanced catalytic performance and anti-coking ability of the Pt-Cu/Al2O3 catalyst is ascribed to the intimate interaction between Pt and Cu, which is confirmed by the change of particle morphology and atomic electronic environment of the catalyst. The Pt-Cu interaction inhibits propylene adsorption and elevates the energy barrier of C-C bond rupture. The inhibited propylene adsorption diminishes the possibility of coke formation and suppresses the cracking reaction towards the formation of lighter hydrocarbons on Pt-Cu/Al2O3, while a higher energy barrier for C-C bond cleavage suppresses the methane formation.

show abstract

Section: Characterization Of Fresh Catalystssupporting

confidence: 91%

Section: Characterization Of Fresh Catalystsmentioning

confidence: 82%

Propane dehydrogenation over Pt–Cu bimetallic catalysts: the nature of coke deposition and the role of copper

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Significantly,the existence of isolated metal sites is not ap rerequisite factor for the inhibition of methanation and sole production of CO in CO 2 hydrogenation reaction. Instead, we believe that the reason behind the size effect is the modulation of the chemical state of Ir species by the substrate, CeO 2 .Ithas been pointed out that the interaction between partially oxidized Ir NPs and CO adsorbent is weaker than that between metallic Ir and CO. [18] In the current case,w hile the partially oxidized Ir/CeO 2 surface can catalyze the dissociative chemisorption and further reaction of CO 2 , the desorption of resulting CO on this partially oxidized Ir species is apt to occur (than further dissociation/hydrogenation to get CH 4 ), giving an ear 100 %s electivity towards CO.N otably, the isolated Ir species and the smaller Ir NPs display identical catalytic selectivity for CO (100 %) in the CO 2 hydrogenation reaction. Despite as ignificant difference in dimensions (one is as ingle metal, and the other is a1nm particle), the observation strongly suggests as imilarity in chemical state of the two kinds of active sites,which work for CO 2 hydrogenation but not CO hydrogenation.…”

Section: Methodsmentioning

confidence: 99%

Tuning the Selectivity of Catalytic Carbon Dioxide Hydrogenation over Iridium/Cerium Oxide Catalysts with a Strong Metal–Support Interaction

et al. 2017

View full text Add to dashboard Cite

A one-step ligand-free method based on an adsorption-precipitation process was developed to fabricate iridium/cerium oxide (Ir/CeO ) nanocatalysts. Ir species demonstrated a strong metal-support interaction (SMSI) with the CeO substrate. The chemical state of Ir could be finely tuned by altering the loading of the metal. In the carbon dioxide (CO ) hydrogenation reaction it was shown that the chemical state of Ir species-induced by a SMSI-has a major impact on the reaction selectivity. Direct evidence is provided indicating that a single-site catalyst is not a prerequisite for inhibition of methanation and sole production of carbon monoxide (CO) in CO hydrogenation. Instead, modulation of the chemical state of metal species by a strong metal-support interaction is more important for regulation of the observed selectivity (metallic Ir particles select for methane while partially oxidized Ir species select for CO production). The study provides insight into heterogeneous catalysts at nano, sub-nano, and atomic scales.

show abstract

“…In detail, bands at ca. 2072-2077 cm −1 and 2015-2042 cm −1 are ascribed to CO linearly adsorbed on highly coordinated Ir 0 located on single-crystal planes and low coordinated Ir 0 located on the edges and corners [30][31][32], respectively. Additionally, the band at 2072 cm −1 in the Ir/TiO2-A blue shifts to 2077 cm −1 in the Ir/TiO2-N, indicating that the stronger interaction of Ir NPs with the support in the The in situ CO-DRIFTS technique was employed to further probe the electronic properties of the Ir species in the pre-reduced Ir/TiO 2 catalysts.…”

Section: Characterizations Of the Catalystmentioning

confidence: 99%

The Roles of Precursor-Induced Metal–Support Interaction on the Selective Hydrogenation of Crotonaldehyde over Ir/TiO2 Catalysts

et al. 2021

View full text Add to dashboard Cite

Various supported Ir/TiO2 catalysts were prepared using different Ir precursors (i.e., H2IrCl6, (NH4)2IrCl6 and Ir(acac)3) and tested for vapor phase selective hydrogenation of crotonaldehyde. The choice of Ir precursor significantly altered the Ir-TiOx interaction in the catalyst, which thus had essential influences on the geometric and electronic properties of the Ir species, reducibility, and surface acidity, and, consequently, their reaction behaviors. The Ir/TiO2-N catalyst using (NH4)2IrCl6 as the precursor gave the highest initial reaction rates and turnover frequencies of crotyl alcohol formation. Such high performance was ascribed to the high Ir dispersion and high surface concentration of Ir0 species, as well as a higher surface acidity, in the Ir/TiO2-N catalyst compared to its counterparts, indicating the synergistic roles of the Ir-TiOx interface in the reaction, as the interfacial sites were responsible for the adsorption/activation of H2 and the C=O bond in the crotonaldehyde molecule.

show abstract

The effect of particle size in the adsorption of carbon monoxide on iridium: An infrared investigation

Cited by 67 publications

References 34 publications

Propane dehydrogenation over Pt–Cu bimetallic catalysts: the nature of coke deposition and the role of copper

Propane dehydrogenation over Pt–Cu bimetallic catalysts: the nature of coke deposition and the role of copper

Tuning the Selectivity of Catalytic Carbon Dioxide Hydrogenation over Iridium/Cerium Oxide Catalysts with a Strong Metal–Support Interaction

The Roles of Precursor-Induced Metal–Support Interaction on the Selective Hydrogenation of Crotonaldehyde over Ir/TiO2 Catalysts

Contact Info

Product

Resources

About